INFORMATION INPUT DEVICE

PROBLEM TO BE SOLVED: To provide an information input device capable of protecting an electric circuit from being destructed by extraneous static electricity while downsizing buttons, dials, and the like.SOLUTION: An information input device includes: a key top; a cover for holding the key top; a dome switch 102 for detecting depression of the key top; a substrate 100 having the dome switch; an insulation sheet 103 disposed on the substrate surface; a holding sheet 104 for holding the dome switch on the substrate; a first signal disposed on the substrate; a second signal disposed on the substrate; detection means for detecting that at least any two or more key tops are pressed according to the combination of the first signal and the second signal. On the substrate, a ground pattern is formed at the portion of the shortest distance between the key top and the camera inner side in cover clearance terminal end, in which an insulation sheet and a holding sheet are cut out at one part thereof.